Improved rock-drill



N. P. BR'ADISH, OF .IERSEYVILLE, ILLINOIS.

Letters Patent No. 92,005, dated June 29, 1869; antedated June-18, 1869.

nvrpnovnn ROCK-DRILL.

MP-o*- The Schedule referred to in ,these Letters Patent and making part of the same.

To all 'whom it may concern:

Be it known that I, N. P. BRADIsH, of Jerseyville, in the county of Jersey, and State of Illinois, have invented a new and improved Rock-Drill; and I do hereby'declare that the following is a full and exact description vof the same, reference being had to the accompanying drawings, and to the letters -of reference marked thereon.

This invention relates to certainimprovements in machines for drilling rocks; and consists ,principally in certain novel devices for holdingr and raising'the drills, and also in sundry details of construction, all of which will be fully described hereinafter.

In thedrawings- Figure 1 represents a proved machine;

Figure 2, a4 front elevation;

Figure-3,'a sectional `-elevation; and

Figures 4, 5, and 6, views of parts detached.

perspective view of my im- To enable those skilled in the art to which my in-' vention appertains, to make and use the same, I will now proceed to describe its construction and operation.

A A represent the base of the machine, from which lise the standards Al A2, suitably connected by crosspieces, as shown.

B represents a shaft, turning in bearings in standards A, upon which are located the double cams G C. These lcams Vary in number according to the size of the machine. 4

They are secured to the shaft by means of a setscrew or other suitable fastening, and are bevelled upon their outer faces from the centre to the sides.

Motion is communicated to the shaft by means of a crank or other suitable connection.

D D represent arms, hinged at their lower ends to the front cross-bean1 D, which are connected at vtheir upper ends to the arms E Il, by means of the ball-andsocket joint e.

The arms D are grooved upon that side which comes 'in contact with the cams C, in such manner as to correspond with the faces of the latter.

D2 D2 represent balls or weights attached to rods d d, extending at right angles from the arms D.

By means of this arrangement, thelatter are over balanced, and are caused to fall naturally against the cams when free to move.

The arms E E extend upward, and are loosely at tached to the drills F F by means of the clasp H.

This clasp is nearly square in shape, and has but three sides, the fourth being closed, when the drill is in place, by means 'of the bent and weighted rod h, which is swung around the drill, and sprung into place behind the drill on top of the clasp. i

Within the clasp is a bar,.h, which is square in form, but is provided with round journals, so that it may at all times freely revolve.

the shaft B in dii'erent lines,

The'clasp H is connected to the arms E by means'- extending out from them at a suitable angle, in which are placedthe guide-rods K K, between which move the bars E E. v

It will be observed that the cams C C are set upon so that the arms D D are not all acted `upon at once, but at different times, by which arrangement greater stcadiness oi' motion is secured.

The arms of these cams are also twisted a little to one side, the purpose of which will beexplained hereafter.

From this description, the operation of my improved machine will be fully understood.

Motionhaving been communicated to the shaft B, the cams O are caused to revolve, which, striking against the arms D, force the latter forward. This .movement necessarily forces the arms E in an upward `direction,fand they carry with them the drills' F F,

which are securely held by the clasp H. As the arms E approach the vertical position, the clasp relaxes its hold, and thedrill falls. As soon as the end of the cam passes by the end of arm D, the latter instantly falls back to the inner end of the opposite cam, and commences a new movement. This instantaneous movement is secured by means of the weights Dl D.

The operation ofthe clasp His as follows:

As the arm E is moving upward, the drill is clamped between the lower edge of the clasp and the bar h', as clearly shown in g. 3, and is thus lifted. As soon, however, as the arm E- approaches a vertical position, the clasp H necessarily assumes a horizontal one, and the drill is left free to fall. This change of position of the clasp is clearly shown in iig. 4. The point e' of the arm E, pressing against the clasp, forces it suddenly upward, and its hold is consequently relaxed.

In order that the drills may work effectively, it is essential that they should turn slightly before each fall. This is accomplished by twisting the cams slightly out of line, and causing them to unite with the arms D, by means of the bevelled and described.

. By this construction, before -the cams leave the arms D, they force them slightly to one side. This movement necessarily causes the lower end of arms E also grooved surfaces, as

to be moved in that direction, (the ball-and-sockerv l joint allowing such freedom of motion,) but as the scribed, in combination with grooved arms D and arm E, constructed and arranged as described, for the purpose set forth.

2; The amis D and E, when connected by means of the holland-socket joint, as and for the purpose set forth.

3. The clasp H, tooth-arm h, and bar h', when oonstructed its described, and operated as and for the purpose set forth.

4. The drilling-machine described, consisting of the cztms C, arms D E, clasp H, .drills F, and frame I, the

whole being constructed, combined, and arranged in the manner and for the purpose set forth. l

rlhis specification signed :nid witnessed, this 17th day of September, .1868.

N. P. BRADISH. Witnesses: H. KRUMPAMTZKY,

GEO. W. W ARE. 

